GrainViolation
source: marts: marts.order_items.measures.shipping
measure 'shipping' has grain 'order' (one row per order), not the mart's grain 'order_item' (one row per line on an order) — measure grain must strictly equal mart grain (S-0027/D-2). Flattened into the mart it is duplicated once per 'order_item' row and any SUM over it overstates. Fix: remove it from this mart's measures, or serve it from a mart at grain 'order'
